Resend check for rent from joint account, but signed by leaseholder. Send by certified mail. If LL accepts, end of story. If LL rejects, the poster should stick to his guns. Send next month the same way. If the LL keeps rejecting, he's likely to try to file for a non-payment eviction. However, the returned checks/and or certified mail receipts would be plenty of evidence that the tenant tried to pay by a legitimate means, and the LL will very likely get tossed out of court.

And of course this would be a good means of establishing a domestic partnership relationship for means of succession.

: LL accepted the joint check before because it was signed by the tenant and probably didn't think much of it- LL may now realize or have reason to believe you're trying to segue into something else- namely establishing a LT relationship with the girlfriend-trying to get LL to accept the girlfriend as payor on the lease.: Tenant should pay rent from his own checking account, one in his name only.: If were a LL I would probably now insist upon the tenant of record being the only payor. Unless you want to fight for recognition of domestic partnership rights or something like that.